FPGA Based Portable Spectrum Analyzer

Abstract

With the progress of Field programmable gate arrays (FPGAs) in performance efficiency and effective utilization of resources, they can be efficiently used for the applications that require real time response. One such application is FPGA based spectrum analyzer that is  Portable  Small in size  allows short duration signals to be analyzed in more detail  Cost- effective

The use of an FPGA provides a flexible instrument as desired for use in testing of integrated circuits that sweeps over a wide range of frequencies up to several GHz range to observe the maximum amplitude frequency component and the corresponding power component for the signal under test. Observation of vibration spectrum will help to detect vibrations that may cause fault or danger, making it possible to troubleshoot engines.

Vibrations (input signal) that are analog signals are first sent to analog to digital converter (ADC) implemented on FPGA and then these digital signals are transformed through Fast Fourier transform (FFT) to the frequency domain to observe the required spectrum where several types of digital filters are employed to observe the frequency lobes for fine tuning. Final spectrum will be displayed and analyzed on LCD with some of the functionalities like adjustable sampling frequency, frequency window settings and storage of time domain waveforms with corresponding spectrum curve.

Project implementation is done on XSA 200 and XSA 1000 board that have Spartan 2 (XC2S200-5FG256) with 200k and 1000k gate density. ADC0808 is used for data conversion and HPL1706 LCD is used for display purposes.